Glass doors are typically equipped with top and bottom pivots or slides which are installed using patch fittings. A door closer mechanism may also be incorporated with the top or bottom pivot or slide. It is known to secure such doors using either manual or electromechanical locks. These may be mounted either within the door or alternatively in the surrounding frame which may be made of glass, timber or alloy. In particular, for overhead installations at the top of the door electromechanical locks are preferred. However, with transparent glass doors and walls there is a problem with concealment of the wires. With bottom installations it is known to use either manual or electrically operated locks mounted with patch fittings to the lower edge of the door. These typically comprise swing bolts, drop bolts, latches or other vertical locking systems. One problem with floor mounted locks is that dirt accumulates in the floor cavity for the bolt or latch and this inhibits operation of the lock. Also, with both overhead and bottom mounted locks as currently known the door must be accurately positioned at the closed position across the centre-line of the door-sill before the lock can engage. This is a problem with through swinging or bi-directional doors where mechanical stops cannot be fitted. Hydraulic closers are of limited benefit here as the door can still “float” out of centre position by as much as ±20 mm due to manufacturing tolerances in the closure mechanism, wear and wind loading.